Add returns_twice to functions that are known to return twice. This implements

the same behavior of gcc by keeping the attribute out of the function type.

llvm-svn: 141803

3 files changed, 24 insertions, 1 deletions

diff --git a/clang/test/Analysis/security-syntax-checks.m b/clang/test/Analysis/security-syntax-checks.m
index a04401b531f..6fb5b3cf14e 100644
--- a/clang/test/Analysis/security-syntax-checks.m
+++ b/clang/test/Analysis/security-syntax-checks.m
@@ -170,7 +170,7 @@ void test_strcat() {
 //===----------------------------------------------------------------------===
 typedef int __int32_t;
 typedef __int32_t pid_t;
-pid_t vfork(void);
+pid_t vfork(void); //expected-warning{{declaration of built-in function 'vfork' requires inclusion of the header <setjmp.h>}}
 
 void test_vfork() {
   vfork(); //expected-warning{{Call to function 'vfork' is insecure as it can lead to denial of service situations in the parent process.}}
diff --git a/clang/test/CodeGen/function-attributes.c b/clang/test/CodeGen/function-attributes.c
index fd98458c842..6cbf40ba220 100644
--- a/clang/test/CodeGen/function-attributes.c
+++ b/clang/test/CodeGen/function-attributes.c
@@ -100,3 +100,14 @@ __attribute__ ((returns_twice)) void f17(void);
 __attribute__ ((returns_twice)) void f18(void) {
         f17();
 }
+
+// CHECK: define void @f19()
+// CHECK: {
+// CHECK: call i32 @setjmp(i32* null)
+// CHECK: returns_twice
+// CHECK: ret void
+typedef int jmp_buf[((9 * 2) + 3 + 16)];
+int setjmp(jmp_buf);
+void f19(void) {
+  setjmp(0);
+}
diff --git a/clang/test/Sema/attr-returns-twice.c b/clang/test/Sema/attr-returns-twice.c
new file mode 100644
index 00000000000..13f53e36de7
--- /dev/null
+++ b/clang/test/Sema/attr-returns-twice.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+
+int a __attribute__((returns_twice)); // expected-warning {{'returns_twice' attribute only applies to functions}}
+
+__attribute__((returns_twice)) void t0(void) {
+}
+
+void t1() __attribute__((returns_twice));
+
+void t2() __attribute__((returns_twice(2))); // expected-error {{attribute takes no arguments}}
+
+typedef void (*t3)(void) __attribute__((returns_twice)); // expected-warning {{'returns_twice' attribute only applies to functions}}